It could be Chopper. Since Chopper is a doctor and Reiju has some medical knowledge, they might bond over sharing medical techniques and treating the crew's injuries. Also, Chopper's kind - hearted nature would make him a great friend for Reiju who might be used to a more cut - throat family environment.
If Naruto was raised by the Straw Hats, he'd probably be a very different person. He might be more carefree like Luffy. For example, he'd be used to the wacky adventures on the Grand Line. His ninja skills could blend with the pirates' combat styles, creating some really unique fighting techniques.
Well, as of the latest manga chapters, Yamato has indeed become a part of the Straw Hats. This decision brings new dynamics and adventures to the crew.
His personality would become more outgoing and adventurous. The Straw Hats' lifestyle is full of exploration, so Naruto would be more eager to take risks.
I really like the fanfiction where the Straw Hats time travel to the future. In this story, they see how their actions have affected the world in the long run. It shows a post - apocalyptic world that was caused by a series of events that they were unknowingly a part of. It makes them reflect on their current actions and how they can change things for the better. Another good one is the one where they go back to the time of Gol D. Roger. They get to meet the legendary pirate and learn some of his secrets, which is really exciting for fans of the series.
Well, he'd bring his unique ninja skills. His shadow clone jutsu could be super useful for various tasks on the ship, like handling multiple chores at once. And his rasengan could be a powerful attack against any strong enemies they face. Also, his never - give - up attitude would fit right in with the Straw Hats' spirit.
Well, in this fanfiction, the Straw Hats might be in need of a powerful ally. They meet Hancock, and she is instantly drawn to Luffy. The crew could then face a common enemy that is threatening both Amazon Lily and their own goals. Hancock decides to join forces with the Straw Hats. Sanji would be over the moon to have Hancock around, but also a bit jealous of Luffy's special connection with her. And Zoro would be his usual stoic self, just glad to have extra muscle for the upcoming battles.
Kizaru could also be interesting. His light - based powers are extremely powerful. If he joined the Straw Hats, he could use his speed and laser - like attacks to protect the crew. However, he would need to change his loyalty from the World Government, which could create a complex and engaging storyline.